Public buildings utilize numerous exit signs indicating exit routes to the exterior of the building. The exit signs normally have at least one face with the word EXIT disposed thereon and bulbs behind the face for illuminating a normally red translucent covering over the word EXIT. The exit signs remain on twenty-four (24) hours a day and frequently utilize special bulbs which have a short life and are expensive. Further, most exit signs have two electrical sockets for receiving two bulbs within the sign. These sockets are variably positioned within the exit sign box in that they may extend from the sides or from the ends.
Fluorescent tubes could more efficiently be utilized in the exit signs, as they would experience longer life and use significantly less energy. There is not now, however, available any fluorescent tube assembly which may be utilized in an exit sign, particularly to retrofit an existing sign having bulb sockets. Retrofitting requires flexibility in the assembly to allow access to the bulb while making the assembly adaptable to various shaped and wire exit sign housings.
Many existing exit signs have opposite faces which must be illuminated. In retrofitting a fluorescent tube assembly for an exit sign fixture, the assembly must be adapted to illuminate both faces of the exit sign while providing an efficient use of energy. Further, the assembly must illuminate the entire face of the exit sign fixture box, not leaving darkened areas.
In assemblies adapted to mount a fluorescent tube within an exit sign, the fixture supporting the tube is generally connected directly to the exit sign box and wires lead from the box to a connector which is threadedly inserted into a socket in the exit sign. Since the connector must be threadably engaged within the socket, mounting of the connector within the socket tends to twist the interconnecting wires to the body of fixture. Stresses on the wires can break the connections and create a dangerous situation. These prior art structures require the light fixture to be mounted within the exit sign box thereby requiring extensive alterations of the box to adapt the box to the fixture.
Electrical fixtures are known in the art which support fluorescent tubes for illumination and include a connector for engaging the conventional threaded bulb socket. An example of one such fixture is shown in U.S. Pat. No. 2,871,455 granted Jan. 27, 1959 to N. H. Richardson. That assembly includes an elongated body for supporting two fluorescent tubes with an electrical connector extending from one side of the body midway of the length thereof. Thus, that assembly is positioned in the open space in front of a socket and because of its configuration would not be satisfactory for disposition within an exit sign.